A range of printer types have evolved wherein an image is constructed from ink selectively applied to a page in dot format. In U.S. Pat. No. 6,045,710 titled ‘Self-aligned construction and manufacturing process for monolithic print heads’ to the inventor Kia Silverbrook there is set out an assessment of the prior art to drop on demand printers along with its manufacturing process.
A microelectomechanical drop on demand print head hereafter referred to as a Memjet print head has been described in co-pending United States patent applications filed simultaneously to the present application and hereby incorporated by cross reference:
Our DocketUSSNNumberOur Title7,018,016MJ62USFluidic seal for an ink jet nozzle assembly6,428,142IJ52USInk jet print head having a moving nozzle withan externally arranged actuator6,526,658IJM52USMethod of manufacture of an ink jet print headhaving a moving nozzle with an externallyarranged actuator6,328,417MJ63USInk jet print head nozzle array6,390,591MJ58Nozzle guard for an ink jet print head
The Memjet print head is developed from print head segments that are capable of producing, for example, 1600 dpi bi-level dots of liquid ink across the full width of a page. Dots are easily produced in isolation, allowing dispersed-dot dithering to be exploited to its fullest. Color planes might be printed in perfect registration, allowing ideal dot-on-dot printing. The print head enables high-speed printing using microelectromechanical ink drop technology.
Various methods, systems and apparatus relating to a printed page based communications network that is best worked with high-speed page printing has been disclosed in co-pending United States Patent Applications/granted patents filed simultaneously by the applicant or assignee of the present invention and are hereby incorporated by cross reference:
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Performance of a print head such as the above is dictated by its engine controller. High-speed printing is a matter of development of both the print head and its engine controller. A page wide print head enabled by the above technology needs an engine controller capable of feeding it high rates of drop control signals. A typical page layout may contain a mixture of images, graphics and text. Because of the page-width nature of the above microelectromechanical print head, each page can be printed at a constant speed to avoid creating visible artifacts. This means that the printing speed need not be varied to match the input data rate. Document rasterization and document printing can be decoupled. To ensure the print head has a constant supply of data, a page should not be printed until it is fully rasterized. Ideally rasterization should be able to run ahead of the printer when rasterizing simple pages, buying time to rasterize more complex pages. The engine controller determines the degree to which these functions might be realised.
More speed at the print head depends on development of both print head and its engine controller. The print engine controller architecture needs to be designed to push large volumes of data to the print head at high speed.